Adaptive encoding of fixed codebook in CELP coders

Author

Kim, Hong Kook

Author_Institution

Human & Comput. Interaction Lab., Samsung Adv. Inst. of Technol., Kyungki, South Korea

Volume

1

fYear

1998

fDate

12-15 May 1998

Firstpage

149

Abstract

We propose an adaptive encoding method of fixed codebook in CELP coders and implement an adaptive fixed code excited linear prediction (AF-CELP) speech coder. The AF-CELP exploits the fact that the fixed codebook contribution to the speech signal is also periodic as the adaptive codebook (or pitch filter) contribution. By modeling the fixed codebook with the pitch lag and the gain from the adaptive codebook, the AF-CELP can be implemented at low bit rates as well as low complexity. Listening tests show that a 6.4 kbit/s AF-CELP has a comparable quality to the 8 kbit/s CS-ACELP

Keywords

adaptive codes; linear predictive coding; speech coding; speech intelligibility; vocoders; 6.4 kbit/s; 8 kbit/s; AF-CELP; CELP coders; adaptive codebook; adaptive encoding; adaptive fixed code excited linear prediction; fixed codebook; listening tests; low bit rates; low complexity; pitch filter; pitch lag; speech quality; speech signal; Adaptive filters; Bit rate; Decoding; Encoding; Humans; Information processing; Quantization; Shape; Speech coding; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech and Signal Processing, 1998. Proceedings of the 1998 IEEE International Conference on

Conference_Location

Seattle, WA

ISSN

1520-6149

Print_ISBN

0-7803-4428-6

Type

conf

DOI

10.1109/ICASSP.1998.674389

Filename

674389